Conceptualizing, Measuring, and Mapping State Structures – With an Application to Western Europe, 1950—2015

This paper addresses long-standing challenges in conceptualizing and measuring state structures. It first outlines a novel conceptualization of the unitary/federal distinction and its relation to de/centralization and a/symmetry, from which it derives static and dynamic typologies. It subsequently develops a scheme for measuring de/centralization that is able to capture the conceptual distinction between unitary and federal states. The scheme is then applied to map state structures in Western Europe from 1950—2015. This mapping exercise shows that some states constitutionally defined as federal are best classified as unitary from a political science perspective and others, constitutionally defined as unitary, should be considered de facto federal. By developing a more effective classification of cases for comparative analysis, the paper offers a tool on which theoretical and empirical advances in understanding the causes and effects of state structures can be built.